 However, only Chūzan managed to establish formal relations with Japan's Ashikaga shogunate, having sent a mission in 1403.These political advantages, coupled with control of Naha, the most active port on Okinawa, allowed Chūzan to gain significant political and economic superiority over its two neighbors.It also benefited greatly culturally; trade always brings cultural exchange along with it, and many of the states in the region were experiencing great cultural surges as a result.